CD8+ T cell exhaustion

New opportunities to overcome T cell dysfunction: the role of transcription factors and how to target them

Immune checkpoint blockade (ICB) therapies, which block inhibitory receptors on T cells, can be efficacious in reinvigorating dysfunctional T cell responses. However, most cancers do not respond to these therapies and even in those that respond, tumors can acquire resistance. New strategies are needed to rescue and recruit T cell responses across patient populations and disease states. In this review, we define mechanisms of T cell dysfunction, focusing on key transcription factor (TF) networks. We discuss the complex and sometimes contradictory roles of core TFs in both T cell function and dysfunction. Finally, we review strategies to target TFs using small molecule modulators, which represent a challenging but highly promising opportunity to tune the T cell response toward sustained immunity.

Identification and analysis of microplastic aggregation in CAR-T cells

Microplastics (MPs) are increasingly recognized as contaminants present in various environments and are widely acknowledged as potential hazards to the mammalian immune system. In our study of chimeric antigen receptor T cell (CAR-T) therapy, we observed the presence of MP in CAR-T cell products for the first time. It is worth exploring whether MP could enter CAR-T cells and how they might affect CAR-T cells' functionality. Therefore, we analyzed how MP affected CD19 and BCMA-CAR-T cells. Based on flow cytometry, ELISA, and cytotoxicity analysis of in vitro and in vivo experiments, MP suppressed the activity of CAR-T cells. Subsequent investigation revealed that the exposure of CAR-T cells to varying concentrations of MP resulted in a notable increase in apoptosis, ferroptosis, and exhaustion levels. Furthermore, the hyperactivation of the mTOR signaling pathway in MP-treated CAR-T cells was verified. The partial restoration of CAR-T cell function in MP was achieved by inhibiting the mTOR pathway. MP present a threat to CAR-T cell function due to their role in inducing CAR-T cell apoptosis, ferroptosis, and T-cell exhaustion through the hyperactivation of mTOR signaling pathways.

T cell landscape in the microenvironment of human solid tumors

T cells are the main effectors involved in anti-tumor immunity, mediating most of the adaptive response towards cancer. After priming in lymph nodes, tumor antigens-specific naïve T lymphocytes proliferate and differentiate into effector CD4+ and CD8+ T cells that migrate from periphery into tumor sites aiming to eliminate cancer cells. Then while most effector T cells die, a small fraction persists and recirculates as long-lived memory T cells which generate enhanced immune responses when re-encountering the same antigen. A number of T (and non-T) cell subsets, stably resides in non-lymphoid peripheral tissues and may provide rapid immune response independently of T cells recruited from blood, against the reemergence of cancer cells. When tumor grows, however, tumor cells have evaded immune surveillance of effector cells (NK and CTL cells) which are exhausted, thus favoring the local expansion of T (and non-T) regulatory cells. In this review, the current knowledge of features of T cells present in the tumor microenvironment (TME) of solid adult and pediatric tumors, the mechanisms upregulating immune-checkpoint molecules and transcriptional and epigenetic landscapes leading to dysfunction and exhaustion of T effector cells are reviewed. The interaction of T cells with cancer- or TME non-neoplastic cells and their secreted molecules shape the T cell profile compromising the intrinsic plasticity of T cells and, therefore, favoring immune evasion. In this phase regulatory T cells contribute to maintain a high immunosuppressive TME thus facilitating tumor cell proliferation and metastatic spread. Despite the advancements of cancer immunotherapy, many tumors are unresponsive to immune checkpoint inhibitors, or therapeutical vaccines or CAR T cell-based adoptive therapy: some novel strategies to improve these T cell-based treatments are lastly proposed.

Effect of Nicotinamide Riboside Against the Exhaustion of CD8+ T Cells via Alleviating Mitochondrial Dysfunction

Background: Targeting mitochondria and protecting the mitochondrial function of CD8+ T cells are crucial for enhancing the clinical efficacy of cancer immunotherapy. Objectives: In this study, our objective was to investigate the potential of nicotinamide riboside (NR) in preserving the mitochondrial function of CD8+ T cells and mitigating their exhaustion. Methods: We established two in vitro models to induce CD8+ T cell exhaustion either by tumor cell-conditioned medium (TCM) or by continuous stimulation with OVA(257-264) peptide. CD8+ T cells were treated in the absence/presence of NR. Results: Our findings demonstrated that NR supplementation effectively inhibited CD8+ T cell exhaustion and preserved mitochondrial function in both models. Moreover, apoptosis of CD8+ T cells was reduced after NR treatment. Western blot data indicated that NR treatment upregulated Silent information regulator 1 (SirT1) expression. Further inhibition of Sirt1 activity using EX527 uncovered that the inhibitory effect of NR on CD8+ T cell exhaustion and its protective effect on mitochondria were attenuated. Conclusions: In conclusion, our results indicate that NR supplementation attenuates CD8+ T cell exhaustion, and its underlying mechanism is associated with increased mitochondrial function regulated by the SirT1 pathway. Our research provides evidence that NR may assist in enhancing the clinical efficacy of immunotherapy.

Cuproptosis-Associated lncRNA Gene Signature Establishes New Prognostic Profile and Predicts Immunotherapy Response in Endometrial Carcinoma

Uterine corpus endometrial carcinoma (UCEC), a prevalent kind of cancerous tumor in female reproductive system that has a dismal prognosis in women worldwide. Given the very limited studies of cuproptosis-related lncRNAs (CRLs) in UCEC. Our purpose was to construct a prognostic profile based on CRLs and explore its assess prognostic value in UCEC victims and its correlation with the immunological microenvironment.

METHODS

554 UCEC tumor samples and 23 normal samples' RNA-seq statistics and clinical details were compiled from data in the TCGA database. CRLs were obtained using Pearson correlation analysis. Using LASSO Cox regression, multivariate Cox regression, and univariate Cox regression analysis, six CRLs are confirmed to develop a risk prediction model at last.We identified two main molecular subtypes and observed that multilayer CRLs modifications were related to patient clinicopathological features, prognosis, and tumor microenvironment (TME) cell infiltration characteristics, and then we verified the prognostic hallmark of UCEC and examined its immunological landscape.Finally, using qRT-PCR, model hub genes' expression patterns were confirmed.

RESULTS

A unique CRL signature was established by the combination of six differently expressed CRLs that were highly linked with the prognosis of UCEC patients. According to their CRLs signatures, the patients were divided into two groups: the low-risk and the high-risk groups. Compared to individuals at high risk, patients at low risk had higher survival rates (p < 0.001). Additionally, Cox regression reveals that the profiles of lncRNAs linked to cuproptosis may independently predict prognosis in UCEC patients. The 1-, 3-, and 5-year risks' respective receiver operating characteristics (ROC) exhibited AUC values of 0.778, 0.810, and 0.854. Likewise, the signature could predict survival in different groups based on factors like stage, age, and grade, among others. Further investigation revealed differences between the different risk score groups in terms of drug sensitivity,immune cell infiltration,tumor mutation burden (TMB) score and microsatellite instability (MSI) score. Compared to the group of high risk, the low-risk group had greater rates of TMB and MSI. Results from qRT-PCR revealed that in UCEC vs normal tissues, AC026202.2, NRAV, AC079466.2, and AC090617.5 were upregulated,while LINC01545 and AL450384.1 were downregulated.

CONCLUSIONS

Our research clarified the relationship between CRLs signature and the immunological profile and prognosis of UCEC.This signature will establish the framework for future investigations into the endometrial cancer CRLs mechanism as well as the exploitation of new diagnostic tools and new therapeutic.

Reversal of T-cell exhaustion: Mechanisms and synergistic approaches

T cells suffer from long-term antigen stimulation and insufficient energy supply, leading to a decline in their effector functions, memory capabilities, and proliferative capacity, ultimately resulting in T cell exhaustion and an inability to perform normal immune functions in the tumor microenvironment. Therefore, exploring how to restore these exhausted T cells to a state with effector functions is of great significance. Exhausted T cells exhibit a spectrum of molecular alterations, such as heightened expression of inhibitory receptors, shifts in transcription factor profiles, and modifications across epigenetic, metabolic, and transcriptional landscapes. This review provides a comprehensive overview of various strategies to reverse T cell exhaustion, including immune checkpoint blockade, and explores the potential synergistic effects of combining multiple approaches to reverse T cell exhaustion. It offers new insights and methods for achieving more durable and effective reversal of T cell exhaustion.

Harnessing immune cells to leverage PARP inhibitors

Homologous-recombination deficiency in DNA repair characterizes a unique group of cancers that are vulnerable to PARP inhibitors and cytotoxic chemotherapy. In this issue of Cell, Luo et al., demonstrated that this genetic attribute in cancer cells may reprogram tumor immune microenvironment and show promise of targeting effector-Treg cells.

T cell exhaustion in human cancers

T cell exhaustion refers to a progressive state in which T cells become functionally impaired due to sustained antigenic stimulation, which is characterized by increased expression of immune inhibitory receptors, but weakened effector functions, reduced self-renewal capacity, altered epigenetics, transcriptional programme and metabolism. T cell exhaustion is one of the major causes leading to immune escape of cancer, creating an environment that supports tumor development and metastatic spread. In addition, T cell exhaustion plays a pivotal role to the efficacy of current immunotherapies for cancer. This review aims to provide a comprehensive view of roles of T cell exhaustion in cancer development and progression. We summerized the regulatory mechanisms that involved in T cell exhaustion, including transcription factors, epigenetic and metabolic reprogramming events, and various microenvironmental factors such as cytokines, microorganisms, and tumor autocrine substances. The paper also discussed the challenges posed by T cell exhaustion to cancer immunotherapies, including immune checkpoint blockade (ICB) therapies and chimeric antigen receptor T cell (CAR-T) therapy, highlightsing the obstacles encountered in ICB therapies and CAR-T therapies due to T cell exhaustion. Finally, the article provides an overview of current therapeutic options aimed to reversing or alleviating T cell exhaustion in ICB and CAR-T therapies. These therapeutic approaches seek to overcome T cell exhaustion and enhance the effectiveness of immunotherapies in treating tumors.

ARHGAP4 promotes colon cancer metastasis through the TGF-β signaling pathway and may be associated with T cell exhaustion

BACKGROUND

Colon cancer is a prevalent invasive neoplasm in the gastrointestinal system with a high degree of malignancy. Despite extensive research, the underlying mechanisms of its recurrence and metastasis remain elusive.Rho GTPase activating protein 4 (ARHGAP4), a member of the small GTPases protein family, may be closely related to tumor metastasis, and its expression is increased in colon cancer. However, the role of ARHGAP4 in colon cancer metastasis is uncertain. This study investigates the impact of ARHGAP4 on the metastasis of colon cancer cells. Our objective is to determine the role of ARHGAP4 in regulating the invasive behavior of colon cancer cells.

METHODS

We downloaded colon adenocarcinoma (COAD) data from the Cancer Genome Atlas (TCGA), and performed differential analysis and survival analysis. By using the CIBERSORT algorithm, we evaluated the proportion of infiltrating immune cells in colon cancer. We further analyzed whether ARHGAP4 is associated with T cell exhaustion. Finally, we investigated the impact of ARHGAP4 knockdown on the migration and invasion of colon cancer cells through in vitro cell experiments. Additionally, we utilized western blotting to assess the expression of protein related to the TGF-β signaling pathway and epithelial-mesenchymal transition (EMT).

RESULTS

We found that ARHGAP4 is upregulated in colon cancer. Subsequent survival analysis revealed that the high-expression group had significantly lower survival rates compared to the low-expression group. Immune infiltration analysis showed that ARHGAP4 was not only positively correlated with CD8+ T cells, but also positively correlated with T cell exhaustion markers programmed cell death 1 (PDCD-1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), and lymphocyte activating 3 (LAG-3). In vitro cell experiments, the knockdown of ARHGAP4 inhibited the migration and invasion of colon cancer cells. Among EMT-related proteins, when ARHGAP4 was knocked down, the expression of E-cadherin was increased, while the expression of N-cadherin and Vimentin was decreased. Meanwhile, the expression of TGF-β1, p-Smad2, and p-Smad3, which are associated with the TGF-β/Smad pathway, all decreased.

CONCLUSION

ARHGAP4 promotes colon cancer metastasis through the TGF-β/Smad signaling pathway and may be associated with T cell exhaustion. It plays an important role in the progression of colon cancer and may serve as a potential target for diagnosis and treatment of colon cancer.

Exploring the role of the immune microenvironment in hepatocellular carcinoma: Implications for immunotherapy and drug resistance

Hepatocellular carcinoma (HCC), the most common type of liver tumor, is a leading cause of cancer-related deaths, and the incidence of liver cancer is still increasing worldwide. Curative hepatectomy or liver transplantation is only indicated for a small population of patients with early-stage HCC. However, most patients with HCC are not candidates for radical resection due to disease progression, leading to the choice of the conventional tyrosine kinase inhibitor drug sorafenib as first-line treatment. In the past few years, immunotherapy, mainly immune checkpoint inhibitors (ICIs), has revolutionized the clinical strategy for HCC. Combination therapy with ICIs has proven more effective than sorafenib, and clinical trials have been conducted to apply these therapies to patients. Despite significant progress in immunotherapy, the molecular mechanisms behind it remain unclear, and immune resistance is often challenging to overcome. Several studies have pointed out that the complex intercellular communication network in the immune microenvironment of HCC regulates tumor escape and drug resistance to immune response. This underscores the urgent need to analyze the immune microenvironment of HCC. This review describes the immunosuppressive cell populations in the immune microenvironment of HCC, as well as the related clinical trials, aiming to provide insights for the next generation of precision immunotherapy.

Prognostic Value of Insulin Growth Factor-Like Receptor 1 (IGFLR1) in Stage II and III Colorectal Cancer and Its Association with Immune Cell Infiltration

IGFLR1 is a novel biomarker, and some evidences suggested that is involved in the immune microenvironment of CRC. Here, we explored the expression of IGFLR1 and its association with the prognosis as well as immune cell infiltration in CRC, with the aim to provide a basis for further studies on IGFLR1. Immunohistochemical staining for IGFLR1, TIM-3, FOXP3, CD4, CD8, and PD-1 was performed in eligible tissues to analyze the expression of IGFLR1 and its association with prognosis and immune cell infiltration. Then, we screened colon cancer samples from TCGA and grouped patients according to IGFLR1-related genes. We also evaluated the co-expression and immune-related pathways of IGFLR1 to identify the potential mechanism of it in CRC. When P < 0.05, the results were considered statistically significant. IGFLR1 and IGFLR1-related genes were associated with the prognosis and immune cell infiltration (P < 0.05). In stage II and III CRC tissue and normal tissue, we found (1) IGFLR1 was expressed in both the cell membrane and cytoplasm and which was differentially expressed between cancer tissue and normal tissue. IGFLR1 expression was associated with the expression of FOXP3, CD8, and gender but was not associated with microsatellite instability. (2) IGFLR1 was an independent prognostic factor and patients with high IGFLR1 had a better prognosis. (3) A model including IGFLR1, FOXP3, PD-1, and CD4 showed good prognostic stratification ability. (4) There was a significant interaction between IGFLR1 and GATA3, and IGFLR1 had a significant co-expression with related factors in the INFR pathway. IGFLR1 has emerged as a new molecule related to disease prognosis and immune cell infiltration in CRC patients and showed a good ability to predict the prognosis of patients.

FXa-mediated PAR-2 promotes the efficacy of immunotherapy for hepatocellular carcinoma through immune escape and anoikis resistance by inducing PD-L1 transcription

BACKGROUND

The high metastasis rate is one of the main reasons for the poor prognosis of patients with hepatocellular carcinoma (HCC). Coagulation factor Xa (FXa) and its receptor proteinase-activated receptor-2 (PAR-2) proven to promote tumor metastasis in other forms of cancer. Here, we explore the role and mechanism of FXa in the regulation of resistance of anoikis and immune escape of HCC.

METHODS

In vitro and in vivo experiments were conducted to explore the role of FXa in HCC metastasis and its potential mechanism. The effects of FXa inhibitor rivaroxaban on HCC immunotherapy were evaluated using intrahepatic metastasis animal models and clinical trial (No. ChiCTR20000040540). We investigated the potential of FXa inhibition as a treatment for HCC.

RESULTS

FXa was highly expressed in HCC and promoted metastasis by activating PAR-2. Mechanistically, FXa-activated PAR-2 endows HCC cells with the ability of anoikis resistance to survive in the circulating blood by inhibiting the extrinsic apoptosis pathway. Furthermore, suspension stimulation-induced phosphorylation of STAT2, which promotes programmed death-ligand 1 (PD-L1) transcription and inhibits the antitumor effects of immune cells by inhibiting the infiltration of CD8+T cells in tumors and the levels of secreted cytokines. In vivo inhibition of FXa with rivaroxaban reduced HCC metastasis by decreasing PD-L1 expression and exhausting tumor-infiltrating lymphocytes. Notably, the combination of rivaroxaban and anti-programmed death-1 monoclonal antibody (anti-PD-1) programmed Death-1 monoclonal antibody (anti-PD-1) induced synergistic antitumor effects in animal models. Most importantly, rivaroxaban improved the objective response rate of patients with HCC to immune checkpoint inhibitors and prolonged overall survival time.

CONCLUSIONS

FXa-activated PAR-2 promotes anoikis resistance and immune escape in HCC, suggesting the potential for combining coagulation inhibitors and PD-1/PD-L1 immune checkpoint blockade to enhance the therapeutic efficacy of HCC.

Effect of inferior caval valve implantation on circulating immune cells and inflammatory mediators in severe tricuspid regurgitation

BACKGROUND

Interventional valve implantation into the inferior vena cava (CAVI) lowers venous congestion in patients with tricuspid regurgitation (TR). We evaluated the impact of a reduction of abdominal venous congestion following CAVI on circulating immune cells and inflammatory mediators.

METHODS

Patients with severe TR were randomized to optimal medical therapy (OMT) + CAVI (n = 8) or OMT (n = 10). In the OMT + CAVI group, an Edwards Sapien XT valve was implanted into the inferior vena cava. Immune cells and inflammatory mediators were measured in the peripheral blood at baseline and three-month follow-up.

RESULTS

Leukocytes, monocytes, basophils, eosinophils, neutrophils, lymphocytes, B, T and natural killer cells and inflammatory markers (C-reactive protein, interferon-gamma, interleukin-2, -4, -5, -10, and tumor necrosis factor-alpha) did not change substantially between baseline and three-month follow-up within the OMT + CAVI and OMT group.

CONCLUSION

The present data suggest that reduction of venous congestion following OMT + CAVI may not lead to substantial changes in systemic inflammation within a short-term follow-up.

CLINICAL TRIAL REGISTRATION

NCT02387697.

Comprehensive bioinformatics analysis and cell line experiments revealed the important role of CDCA3 in sarcoma

Background

Sarcoma mainly originate from bone and soft tissue and are highly aggressive malignant tumors. Cell division cycle-related protein 3 (CDCA3) is a protein involved in the regulation of the cell cycle, which is highly expressed in a variety of malignant tumors. However, its role in sarcoma remains unclear. This study aims to investigate the function and potential mechanism of CDCA3 in sarcoma and to elucidate its importance in sarcoma.

Methods

We first studied the expression and prognosis of CDCA family members in sarcoma by Oncomine and the Gene Expression Profiling Interactive Analysis (GEPIA). The role of CDCA3 protein in sarcoma was further analyzed by the Cancer Genome Atlas Program (TCGA), the Cancer Cell Lineage Encyclopedia (CCLE), and Linke-dOmics. In addition, immunohistochemistry and Western blot were used to verify the expression of CDCA3 protein in clinical samples as well as sarcoma cell lines (U2OS, SAOS2, MG63, and HOS). Subsequently, in vitro experiments (cloning and scratching experiments) were performed using sh-NC as well as sh-CDCA3 group cells to reveal the biological functions of CDCA3.

Results

We found that the CDCA family (CDCA3, CDCA4, and CDCA8) is highly expressed in sarcoma, and the expression level of CDCA3, CDCA4, and CDCA8 negatively correlates with the prognosis of sarcoma patients. CDCA3 mRNA was highly expressed in pan-cancer by CCLE and TCGA database analysis. KEGG analysis showed that CDCA3 was mainly enriched in the cell cycle signaling pathway (It promoted the transition of the cell cycle from the G0/G1 phase to the S phase). In the level of immune infiltration, CDCA3 was negatively correlated with pDC cells, CD8+T cells, and cytotoxic cells. Finally, patients with high CDCA3 expression in sarcoma were analyzed for resistance to NU7441 and others, while sensitive to Fulvestrant and Dihydrorotenone. Furthermore, we demonstrated high expression of CDCA3 protein in sarcoma tissues and cell lines by immunohistochemistry and Western blot experiments. Cloning, EDU, scratching, and migration experiments showed that the knockdown of CDCA3 inhibited the Proliferation and progression of sarcoma cells.

Conclusion

These results suggest for the first time that knockdown of CDCA3 may inhibit sarcoma progression. CDCA3 may be an effective target for the treatment of sarcoma.

Construction and validation of prognostic signature for transcription factors regulating T cell exhaustion in hepatocellular carcinoma

In the tumor microenvironment (TME), CD8+ T cells showed stage exhaustion due to the continuous stimulation of tumor antigens. To evaluate the status of CD8+ T cells and reverse the exhaustion is the key to evaluate the prognosis and therapeutic effect of tumor patients. The aim of this study was to establish a prognostic signature that could effectively predict prognosis and response to immunotherapy in patients with hepatocellular carcinoma (HCC). We used univariate Cox analysis to obtain transcription factors associated with CD8+ T cell exhaustion from The Cancer Genome Atlas dataset. Then, the prognostic signature for transcription factors basic leucine zipper ATF-like transcription factor, Eomesodermin, and T-box protein 21 regulating T cell exhaustion was constructed using LASSO Cox regression. The relative expression levels of the mRNA of the 3 transcription factors were detected by reverse transcription-quantitative polymerase chain reaction in 23 pairs of HCC and paracancer tissues, and verified internally in The Cancer Genome Atlas dataset and externally in the International Cancer Genome Consortium dataset. Cox regression analysis showed that risk score was an independent prognostic variable. The overall survival of the high-risk group was significantly lower than that of the low-risk group. The low-risk group had higher immune scores, matrix scores, and ESTIMATE scores, and significantly increased expression levels of most immune checkpoint genes in the low-risk group. Therefore, patients with lower risk scores benefit more from immunotherapy. The combination of the 3 transcription factors can evaluate the exhaustion state of CD8+ T cells in the TME, laying a foundation for evaluating the TME and immunotherapy efficacy in patients with HCC.

Glycosylphosphatidylinositol anchor biosynthesis pathway-based biomarker identification with machine learning for prognosis and T cell exhaustion status prediction in breast cancer

As the primary component of anti-tumor immunity, T cells are prone to exhaustion and dysfunction in the tumor microenvironment (TME). A thorough understanding of T cell exhaustion (TEX) in the TME is crucial for effectively addressing TEX in clinical settings and promoting the efficacy of immune checkpoint blockade therapies. In eukaryotes, numerous cell surface proteins are tethered to the plasma membrane via Glycosylphosphatidylinositol (GPI) anchors, which play a crucial role in facilitating the proper translocation of membrane proteins. However, the available evidence is insufficient to support any additional functional involvement of GPI anchors. Here, we investigate the signature of GPI-anchor biosynthesis in the TME of breast cancer (BC)patients, particularly its correlation with TEX. GPI-anchor biosynthesis should be considered as a prognostic risk factor for BC. Patients with high GPI-anchor biosynthesis showed more severe TEX. And the levels of GPI-anchor biosynthesis in exhausted CD8 T cells was higher than normal CD8 T cells, which was not observed between malignant epithelial cells and normal mammary epithelial cells. In addition, we also found that GPI -anchor biosynthesis related genes can be used to diagnose TEX status and predict prognosis in BC patients, both the TEX diagnostic model and the prognostic model showed good AUC values. Finally, we confirmed our findings in cells and clinical samples. Knockdown of PIGU gene expression significantly reduced the proliferation rate of MDA-MB-231 and MCF-7 cell lines. Immunofluorescence results from clinical samples showed reduced aggregation of CD8 T cells in tissues with high expression of GPAA1 and PIGU.

Epigenetic regulation of immune cells in systemic lupus erythematosus: insight from chromatin accessibility

INTRODUCTION

Systemic Lupus Erythematosus (SLE) is a multi-dimensional autoimmune disease involving numerous tissues throughout the body. The chromatin accessibility landscapes in immune cells play a pivotal role in governing their activation, function, and differentiation. Aberrant modulation of chromatin accessibility in immune cells is intimately associated with the onset and progression of SLE.

AREAS COVERED

In this review, we described the chromatin accessibility landscapes in immune cells, summarized the recent evidence of chromatin accessibility related to the pathogenesis of SLE, and discussed the potential of chromatin accessibility as a valuable option to identify novel therapeutic targets for this disease.

EXPERT OPINION

Dynamic changes in chromatin accessibility are intimately related to the pathogenesis of SLE and have emerged as a new direction for exploring its epigenetic mechanisms. The differently accessible chromatin regions in immune cells often contain binding sites for transcription factors (TFs) and cis-regulatory elements such as enhancers and promoters, which may be potential therapeutic targets for SLE. Larger scale cohort studies and integrating epigenomic, transcriptomic, and metabolomic data can provide deeper insights into SLE chromatin biology in the future.

Chidamide enhances T-cell-mediated anti-tumor immune function by inhibiting NOTCH1/NFATC1 signaling pathway in ABC-type diffuse large B-cell lymphoma

Chidamide (CS055/HBI-8000, tucidinostat) has shown promising effects in the clinical treatment of various hematologic tumors. Diffuse large B-cell lymphoma (DLBCL) has shown highly heterogeneous biological characteristics. There are complex mechanisms of the role of chidamide in DLBCL for in-depth study. It is essential to probe further into the mechanism of drug-tumor interactions as a guide to clinical application and to understand the occurrence and progression of DLBCL. In vitro and in vivo models were utilized to determine the effects of chidamide on signaling pathways involved in the DLBCL tumor microenvironment. The experimental results show that chidamide inhibited the proliferation of DLBCL cell lines in a dose- and time-dependent manner, and down-regulated the expression of NOTCH1 and NFATC1 in DLBCL cells as well as decreased the concentration of IL-10 in the supernatant. In addition, chidamide significantly lowered the expression of PD1 or TIM3 on CD4+T cells and CD8+T cells and elevated the levels of IL-2, IFN-γ, and TNF-α in the serum of animal models, which augmented the function of circulating T cells and tumor-infiltrating T cells and ultimately significantly repressed the growth of tumors. These findings prove that chidamide can effectively inhibit the cell activity of DLBCL cell lines by inhibiting the activation of NOTCH1 and NFATC1 signaling pathways. It can also improve the abnormal DLBCL microenvironment in which immune escape occurs, and inhibit immune escape. This study provides a new therapeutic idea for the exploration of individualized precision therapy for patients with malignant lymphoma.

NR4A1 transcriptionally regulates the differentiation of stem-like CD8+ T cells in the tumor microenvironment

CD8+ T cells are rendered exhausted in tumor and chronic infection. Among heterogeneous exhausted T cells, a subpopulation of progenitor-like (Tpex) cells have been found important for long-term tumor or pathogen control and are also the main responders in immunotherapy. Using an RFP reporter mouse for the orphan nuclear receptor NR4A1, originally characterized as critical in T cell dysfunction, we discover that the reporter is highly expressed in Tpex cells in tumor and chronic infection. Enforced expression of Nr4a1 promotes Tpex cell accumulation, whereas tumor control is improved after Nr4a1 deletion, associated with increased effector function but decreased long-term maintenance of CD8+ T cells. Integrating chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) analysis, NR4A1 is found to bind and promote the expression of Tpex-related genes, as well as suppress terminal differentiation-associated genes. This study therefore has identified a key role of NR4A1 in Tpex regulation and provides a promising target for immunotherapy.

Overexpression of LAG-3: a potential indicator of low immune function in tuberculosis

Background

Tuberculosis (TB) persists as a global health challenge, with its treatment hampered by the side effects of long-term combination drug therapies and the growing issue of drug resistance. Therefore, the development of novel therapeutic strategies is critical. This study focuses on the role of immune checkpoint molecules (ICs) and functions of CD8+ T cells in the search for new potential targets against TB.

Methods

We conducted differential expression genes analysis and CD8+ T cell functional gene analysis on 92 TB samples and 61 healthy individual (HI) samples from TB database GSE83456, which contains data on 34,603 genes. The GSE54992 dataset was used to validated the findings. Additionally, a cluster analysis on single-cell data from primates infected with mycobacterium tuberculosis and those vaccinated with BCG was performed.

Results

The overexpression of LAG-3 gene was found as a potentially important characteristic of both pulmonary TB (PTB) and extrapulmonary TB (EPTB). Further correlation analysis showed that LAG-3 gene was correlated with GZMB, perforin, IL-2 and IL-12. A significant temporal and spatial variation in LAG-3 expression was observed in T cells and macrophages during TB infection and after BCG vaccination.

Conclusion

LAG-3 was overexpressed in TB samples. Targeting LAG-3 may represent a potential therapeutic target for tuberculosis.

Heat shock protein 90α reduces CD8+ T cell exhaustion in acute lung injury induced by lipopolysaccharide

CD8+ T-cell exhaustion is a promising prognostic indicator of sepsis-induced acute respiratory distress syndrome (ARDS). Patients with sepsis-related ARDS had reduced levels of HSP90AA1. However, whether the changes in CD8+ T cells were related to HSP90α, encoded by the HSP90AA1 gene, was unclear. This study aimed to examine the regulatory mechanism of HSP90α and its impact on CD8+ T-cell exhaustion in lipopolysaccharide (LPS)-induced acute lung injury (ALI). In this study, by conducting a mouse model of ALI, we found that one week after LPS-induced ALI, CD8+ T cells showed exhaustion characteristics. At this time, proliferation and cytokine release in CD8+ T cells were reduced. The inhibitory costimulatory factors PD-1 and Tim-3, on the other hand, were enhanced. Meanwhile, the expression of HSP90α and STAT1 decreased significantly. The in vitro studies showed that HSP90α stimulation or inhibition affected the CD8+ T-cell exhaustion phenotype. Interference with STAT1 reduced the expression of HSP90α and impaired its regulation of CD8+ T cells. The Co-Immunoprecipitation results indicated that HSP90α can directly or indirectly bind to TOX to regulate TOX expression and downstream signal transduction. In summary, by inhibiting TOX-mediated exhaustion signaling pathways, HSP90α inhibited CD8+ T-cell exhaustion in ALI. The participation of STAT1 in the regulation of HSP90α was required.

Interactions between LAMP3+ dendritic cells and T-cell subpopulations promote immune evasion in papillary thyroid carcinoma

BACKGROUND

The incidence of papillary thyroid cancer (PTC) continues to rise all over the world, 10-15% of the patients have a poor prognosis. Although immunotherapy has been applied in clinical practice, its therapeutic efficacy remains far from satisfactory, necessitating further investigation of the mechanism of PTC immune remodeling and exploration of novel treatment targets.

METHODS

This study conducted a single-cell RNA sequencing (scRNA-seq) analysis using 18 surgical tissue specimens procured from 14 patients diagnosed with adjacent tissues, non-progressive PTC or progressive PTC. Key findings were authenticated through spatial transcriptomics RNA sequencing, immunohistochemistry, multiplex immunohistochemistry, and an independent bulk RNA-seq data set containing 502 samples.

RESULTS

A total of 151,238 individual cells derived from 18 adjacent tissues, non-progressive PTC and progressive PTC specimens underwent scRNA-seq analysis. We found that progressive PTC exhibits the following characteristics: a significant decrease in overall immune cells, enhanced immune evasion of tumor cells, and disrupted antigen presentation function. Moreover, we identified a subpopulation of lysosomal associated membrane protein 3 (LAMP3+) dendritic cells (DCs) exhibiting heightened infiltration in progressive PTC and associated with advanced T stage and poor prognosis of PTC. LAMP3+ DCs promote CD8+ T cells exhaustion (mediated by NECTIN2-TIGIT) and increase infiltration abundance of regulatory T cells (mediated by chemokine (C-C motif) ligand 17 (CCL17)-chemokine (C-C motif) receptor 4 (CCR4)) establishing an immune-suppressive microenvironment. Ultimately, we unveiled that progressive PTC tumor cells facilitate the retention of LAMP3+ DCs within the tumor microenvironment through NECTIN3-NECTIN2 interactions, thereby rendering tumor cells more susceptible to immune evasion.

CONCLUSION

Our findings expound valuable insights into the role of the interaction between LAMP3+ DCs and T-cell subpopulations and offer new and effective ideas and strategies for immunotherapy in patients with progressive PTC.

Single-Cell RNA Sequencing Shows T-Cell Exhaustion Landscape in the Peripheral Blood of Patients with Hepatitis B Virus-Associated Acute-on-Chronic Liver Failure

Background/Aims

The occurrence and development of hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) is closely related to the immune pathway. We explored the heterogeneity of peripheral blood T cell subsets and the characteristics of exhausted T lymphocytes, in an attempt to identify potential therapeutic target molecules for immune dysfunction in ACLF patients.

Methods

A total of 83,577 T cells from HBV-ACLF patients and healthy controls were screened for heterogeneity by single-cell RNA sequencing. In addition, exhausted T-lymphocyte subsets were screened to analyze their gene expression profiles, and their developmental trajectories were investigated. Subsequently, the expression of exhausted T cells and their capacity in secreting cytokines (interleukin 2, interferon γ, and tumor necrosis factor α) were validated by flow cytometry.

Results

A total of eight stable clusters were identified, among which CD4+ TIGIT+ subset and CD8+ LAG-3+ subset, with high expression of exhaust genes, were significantly higher in the HBV-ACLF patients than in normal controls. As shown by pseudotime analysis, T cells experienced a transition from naïve T cells to effector T cells and then exhausted T cells. Flow cytometry confirmed that the CD4+TIGIT+ subset and CD8+LAG-3+ subset in the peripheral blood of the ACLF patients were significantly higher than those in the healthy controls. Moreover, in vitro cultured CD8+LAG-3+ T cells were significantly fewer capable of secreting cytokines than CD8+LAG-3- subset.

Conclusions

Peripheral blood T cells are heterogeneous in HBV-ACLF. The exhausted T cells markedly increase during the pathogenesis of ACLF, suggesting that T-cell exhaustion is involved in the immune dysfunction of HBV-ACLF patients.

Deciphering the potential role of PGRN in regulating CD8+ T cell antitumor immunity

A key factor contributing to resistance in immune checkpoint blockade (ICB) therapies is CD8+ T-cell tolerance in the tumor microenvironment (TME), partly resulting from upregulating coinhibitory receptors. Here, we describe the role of PGRN as a coinhibitory molecule that modulates the antitumor response of CD8+ T cells, thus presenting a novel immunosuppressive target for lung cancer. The in vivo subcutaneous transplanted lung cancer model showed that PGRN expression was elevated on CD8+ T cells that infiltrated transplanted lung cancers. Furthermore, PGRN deficiency was found to specifically encourage the infiltration of CD8+ T cells, enhance their proliferation, migration, and activation, and resist apoptosis, ultimately inhibiting tumor growth. This was achieved by PGRN knockout, increasing the production of T cell chemokine CCL3, which boosts the antitumor immune response induced by CD8+ T cells. Critically, the PD-L1 inhibitor exhibited a synergistic effect in enhancing the antitumor response in PGRN-/- mice. In summary, our findings highlight the significance of PGRN as a novel target for boosting CD8+ T cells antitumor immunity and its potential to overcome the resistance in ICB therapy.

Dual targeting of TIGIT and PD-1 with a novel small molecule for cancer immunotherapy

Immune checkpoint inhibitors have unveiled promising clinical prospects in cancer treatment. Nonetheless, their effectiveness remains restricted, marked by consistently low response rates and affecting only a subset of patients. The co-blockade of TIGIT with PD-1 has exhibited substantial anti-tumor effects. Notably, there is a dearth of reports on small-molecule inhibitors concurrently targeting both TIGIT and PD-1. In this study, we employed Microscale Thermophoresis (MST) to screen our laboratory's existing repository of small molecules. Our findings illuminated Gln(TrT) 's affinity for both TIGIT and PD-1, affirming its potential to effectively inhibit TIGIT/PVR and PD-1/PD-L1 pathways. In vitro co-culture experiments substantiated Gln(TrT)'s proficiency in restoring Jurkat T-cell functionality by blocking both TIGIT/PVR and PD-1/PD-L1 interactions. In the MC38 murine tumor model, Gln(TrT) emerges as a pivotal modulator, promoting the intratumoral infiltration and functional competence of CD8+ T cells. Furthermore, whether used as a monotherapy or in conjunction with radiotherapy, Gln(TrT) substantially impedes MC38 tumor progression, significantly extending the survival of murine subjects.

Upregulation of HLA-II related to LAG-3+CD4+ T cell infiltration is associated with patient outcome in human glioblastoma

Glioblastoma (GBM) is the most common malignant diffuse glioma of the brain. Although immunotherapy with immune checkpoint inhibitors (ICIs), such as programmed cell death protein (PD)-1/PD ligand-1 inhibitors, has revolutionized the treatment of several cancers, the clinical benefit in GBM patients has been limited. Lymphocyte-activation gene 3 (LAG-3) binding to human leukocyte antigen-II (HLA-II) plays an essential role in triggering CD4+ T cell exhaustion and could interfere with the efficiency of anti-PD-1 treatment; however, the value of LAG-3-HLA-II interactions in ICI immunotherapy for GBM patients has not yet been analyzed. Therefore, we aimed to investigate the expression and regulation of HLA-II in human GBM samples and the correlation with LAG-3+CD4+ T cell infiltration. Human leukocyte antigen-II was highly expressed in GBM and correlated with increased LAG-3+CD4+ T cell infiltration in the stroma. Additionally, HLA-IIHighLAG-3High was associated with worse patient survival. Increased interleukin-10 (IL-10) expression was observed in GBM, which was correlated with high levels of HLA-II and LAG-3+ T cell infiltration in stroma. HLA-IIHighIL-10High GBM associated with LAG-3+ T cells infiltration synergistically showed shorter overall survival in patients. Combined anti-LAG-3 and anti-IL-10 treatment inhibited tumor growth in a mouse brain GL261 tumor model. In vitro, CD68+ macrophages upregulated HLA-II expression in GBM cells through tumor necrosis factor-α (TNF-α). Blocking TNF-α-dependent inflammation inhibited tumor growth in a mouse GBM model. In summary, T cell-tumor cell interactions, such as LAG-3-HLA-II, could confer an immunosuppressive environment in human GBM, leading to poor prognosis in patients. Therefore, targeting the LAG-3-HLA-II interaction could be beneficial in ICI immunotherapy to improve the clinical outcome of GBM patients.

To develop a prognostic model for neoadjuvant immunochemotherapy efficacy in esophageal squamous cell carcinoma by analyzing the immune microenvironment

Objective

The choice of neoadjuvant therapy for esophageal squamous cell carcinoma (ESCC) is controversial. This study aims to provide a basis for clinical treatment selection by establishing a predictive model for the efficacy of neoadjuvant immunochemotherapy (NICT).

Methods

A retrospective analysis of 30 patients was conducted, divided into Response and Non-response groups based on whether they achieved major pathological remission (MPR). Differences in genes and immune microenvironment between the two groups were analyzed through next-generation sequencing (NGS) and multiplex immunofluorescence (mIF). Variables most closely related to therapeutic efficacy were selected through LASSO regression and ROC curves to establish a predictive model. An additional 48 patients were prospectively collected as a validation set to verify the model's effectiveness.

Results

NGS suggested seven differential genes (ATM, ATR, BIVM-ERCC5, MAP3K1, PRG, RBM10, and TSHR) between the two groups (P < 0.05). mIF indicated significant differences in the quantity and location of CD3+, PD-L1+, CD3+PD-L1+, CD4+PD-1+, CD4+LAG-3+, CD8+LAG-3+, LAG-3+ between the two groups before treatment (P < 0.05). Dynamic mIF analysis also indicated that CD3+, CD8+, and CD20+ all increased after treatment in both groups, with a more significant increase in CD8+ and CD20+ in the Response group (P < 0.05), and a more significant decrease in PD-L1+ (P < 0.05). The three variables most closely related to therapeutic efficacy were selected through LASSO regression and ROC curves: Tumor area PD-L1+ (AUC= 0.881), CD3+PD-L1+ (AUC= 0.833), and CD3+ (AUC= 0.826), and a predictive model was established. The model showed high performance in both the training set (AUC= 0.938) and the validation set (AUC= 0.832). Compared to the traditional CPS scoring criteria, the model showed significant improvements in accuracy (83.3% vs 70.8%), sensitivity (0.625 vs 0.312), and specificity (0.937 vs 0.906).

Conclusion

NICT treatment may exert anti-tumor effects by enriching immune cells and activating exhausted T cells. Tumor area CD3+, PD-L1+, and CD3+PD-L1+ are closely related to therapeutic efficacy. The model containing these three variables can accurately predict treatment outcomes, providing a reliable basis for the selection of neoadjuvant treatment plans.

The link between obesity and the gut microbiota and immune system in early-life

In early-life, the gut microbiota is highly modifiable, being modulated by external factors such as maternal microbiota, mode of delivery, and feeding strategies. The composition of the child's gut microbiota will deeply impact the development and maturation of its immune system, with consequences for future health. As one of the main sources of microorganisms to the child, the mother represents a crucial factor in the establishment of early-life microbiota, impacting the infant's wellbeing. Recent studies have proposed that dysbiotic maternal gut microbiota could be transmitted to the offspring, influencing the development of its immunity, and leading to the development of diseases such as obesity. This paper aims to review recent findings in gut microbiota and immune system interaction in early-life, highlighting the benefits of a balanced gut microbiota in the regulation of the immune system.

Stem-like CD8 T cells in stage I lung adenocarcinoma as a prognostic biomarker: A preliminary study

OBJECTIVES

This study aimed to investigate the presence of stem-like CD8 T (CD8 TSL) cells in lung adenocarcinoma (LUAD) and explore their relationships with the clinical outcomes.

METHODS

Multiplex immunofluorescence (mIF) was performed to identify CD8 TSL and antigen-presenting cells (APC) in 76 LUAD patients. Differences in the number of CD8 TSL cells based on tumor stage and the spatial relationships between CD8 TSL cells and APC niches were determined. The optimal cutoff value of CD8 TSL cells for predicting survival in patients with stage I LUAD was calculated.

RESULTS

CD8 TSL cells were present in all tumors, and their numbers were significantly higher in stage I patients than in stage III patients (P = 0.010); CD8 TSL cells located in the APC niches accounted for 69.7% (53/76) of the hotspot fields. The optimal cutoff value for the number of CD8 TSL cells required to predict the overall survival (OS) in patients with stage I LUAD was 2.5 per 10000 μm2. The median OS and progression-free survival (PFS) in the high-level group (>2.5) were significantly (P < 0.001) longer than those in the low-level group (≤2.5). The number of CD8 TSL cells was an independent prognostic factor for stage I LUAD. Patients with more CD8 TSL cells had a lower risk of death and disease progression than those with less CD8 TSL cells.

CONCLUSION

CD8 TSL cells were observed in patients with stages I-III LUAD and might serve as prognostic biomarkers for stage I LUAD.

The enhanced antitumor activity of bispecific antibody targeting PD-1/PD-L1 signaling

The programmed cell death 1 (PD-1) signaling pathway, a key player in immune checkpoint regulation, has become a focal point in cancer immunotherapy. In the context of cancer, upregulated PD-L1 on tumor cells can result in T cell exhaustion and immune evasion, fostering tumor progression. The advent of PD-1/PD-L1 inhibitor has demonstrated clinical success by unleashing T cells from exhaustion. Nevertheless, challenges such as resistance and adverse effects have spurred the exploration of innovative strategies, with bispecific antibodies (BsAbs) emerging as a promising frontier. BsAbs offer a multifaceted approach to cancer immunotherapy by simultaneously targeting PD-L1 and other immune regulatory molecules. We focus on recent advancements in PD-1/PD-L1 therapy with a particular emphasis on the development and potential of BsAbs, especially in the context of solid tumors. Various BsAb products targeting PD-1 signaling are discussed, highlighting their unique mechanisms of action and therapeutic potential. Noteworthy examples include anti-TGFβ × PD-L1, anti-CD47 × PD-L1, anti-VEGF × PD-L1, anti-4-1BB × PD-L1, anti-LAG-3 × PD-L1, and anti-PD-1 × CTLA-4 BsAbs. Besides, we summarize ongoing clinical studies evaluating the efficacy and safety of these innovative BsAb agents. By unraveling the intricacies of the tumor microenvironment and harnessing the synergistic effects of anti-PD-1/PD-L1 BsAbs, there exists the potential to elevate the precision and efficacy of cancer immunotherapy, ultimately enabling the development of personalized treatment strategies tailored to individual patient profiles.

Mapping spatial heterogeneity in gastric cancer microenvironment

Gastric cancer (GC) is difficult to characterize due to its heterogeneity, and the complicated heterogeneity leads to the difficulty of precisely targeted therapy. The spatially heterogeneous composition plays a crucial role in GC onset, progression, treatment efficacy, and drug resistance. In recent years, the technological advancements in spatial omics has shifted our understanding of the tumor microenvironment (TME) from cancer-centered model to a dynamic and variant whole. In this review, we concentrated on the spatial heterogeneity within the primary lesions and between the primary and metastatic lesions of GC through the TME heterogeneity including the tertiary lymphoid structures (TLSs), the uniquely spatial organization. Meanwhile, the immune phenotype based on spatial distribution was also outlined. Furthermore, we recapitulated the clinical treatment in mediating spatial heterogeneity in GC, hoping to provide a systematic view of how spatial information could be integrated into anti-cancer immunity.

Maternal urban particulate matter (SRM 1648a) exposure disrupted the cellular immune homeostasis during early life: The potential attribution of altered placental transcriptome profile

Ambient fine particular matter (PM2.5) exposure has been associated with numerous adverse effects including triggering functional disorders of the placenta and inducing immune imbalance in offspring. However, how maternal PM2.5 exposure impacts immune development during early life is not fully understood. In the current study, we exposed mice with low-, middle-, and high-dose PM2.5 during pregnancy to investigate the potential link between the transcriptional changes in the placenta and immune imbalance in mice offspring induced by PM2.5 exposures. Using flow cytometry, we found that the proportions of B cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and macrophage (Mφ) cells were altered in the blood of PM2.5-exposed mice pups but not dendritic cells (DCs) and natural killer cells (NKs). Using bulk RNA sequencing, we found that PM2.5 exposure altered the transcriptional profile which indicated an inhibition of the complement and coagulation cascades in the placenta. Weighted gene co-expression network analysis (WGCNA) revealed the potential crosstalk between the perturbation of placental gene expression and the changes of immune cell subsets in pups on postnatal day 10 (PND10). Specifically, WGCNA identified a cluster of genes including Defb15, Defb20, Defb25, Cst8, Cst12, and Adam7 that might regulate the core immune cell types in PND10 pups. Although the underlying mechanisms of how maternal PM2.5 exposure induces peripheral lymphocyte disturbance in offspring still remain much unknown, our findings here shed light on the potential role of placental dysfunction in these adverse effects.

Regulation of T cells in the tumor microenvironment by histone methylation: LSD1 inhibition-a new direction for enhancing immunotherapy

Although immune checkpoint blockade (ICB) has been shown to achieve durable therapeutic responses in various types of tumors, only 20-40 % of patients benefit from this therapy. A growing body of research suggests that epigenetic modulation of the tumor microenvironment may be a promising direction for enhancing the efficacy of immunotherapy, for example, histone methylation plays an important role in the regulation of T cells in the tumor microenvironment (TME). In particular, histone lysine-specific demethylase 1 (LSD1/KDM1A), as an important histone-modifying enzyme in epigenetics, was found to be an important factor in the regulation of T cells. Therefore, this paper will summarize the effects of histone methylation, especially LSD1, on T cells in the TME to enhance the efficacy of anti-PD-1 immunotherapy. To provide a strong theoretical basis for the strategy of combining LSD1 inhibitors with anti-PD-1/PD-L1 immunotherapy, thus adding new possibilities to improve the survival of tumor patients.

Single-cell RNA sequencing reveals the dynamics and heterogeneity of lymph node immune cells during acute and chronic viral infections

Introduction

The host immune response determines the differential outcome of acute or chronic viral infections. The comprehensive comparison of lymphoid tissue immune cells at the single-cell level between acute and chronic viral infections is largely insufficient.

Methods

To explore the landscape of immune responses to acute and chronic viral infections, single-cell RNA sequencing(scRNA-seq), scTCR-seq and scBCR-seq were utilized to evaluate the longitudinal dynamics and heterogeneity of lymph node CD45+ immune cells in mouse models of acute (LCMV Armstrong) and chronic (LCMV clone 13) viral infections.

Results

In contrast with acute viral infection, chronic viral infection distinctly induced more robust NK cells and plasma cells at the early stage (Day 4 post-infection) and acute stage (Day 8 post-infection), respectively. Moreover, chronic viral infection exerted decreased but aberrantly activated plasmacytoid dendritic cells (pDCs) at the acute phase. Simultaneously, there were significantly increased IgA+ plasma cells (MALT B cells) but differential usage of B-cell receptors in chronic infection. In terms of T-cell responses, Gzma-high effector-like CD8+ T cells were significantly induced at the early stage in chronic infection, which showed temporally reversed gene expression throughout viral infection and the differential usage of the most dominant TCR clonotype. Chronic infection also induced more robust CD4+ T cell responses, including follicular helper T cells (Tfh) and regulatory T cells (Treg). In addition, chronic infection compromised the TCR diversity in both CD8+ and CD4+ T cells.

Discussion

In conclusion, gene expression and TCR/BCR immune repertoire profiling at the single-cell level in this study provide new insights into the dynamic and differential immune responses to acute and chronic viral infections.

Multi-omics reveals the role of ENO1 in bladder cancer and constructs an epithelial-related prognostic model to predict prognosis and efficacy

α-Enolase (ENO1) is a crucial molecular target for tumor therapy and has emerged as a research hotspot in recent decades. Here, we aimed to explore the role of ENO1 in bladder cancer (BLCA) and then construct a signature to predict the prognosis and treatment response of BLCA. Firstly, we found ENO1 was highly expressed in BLCA tissues, as verified by IHC, and was associated with poor prognosis. The analysis of the tumor immune microenvironment by bulk RNA-seq and scRNA-seq showed that ENO1 was associated with CD8+ T-cell exhaustion. Additionally, the results in vitro showed that ENO1 could promote the proliferation and invasion of BLCA cells. Then, the analysis of epithelial cells (ECs) revealed that ENO1 might promote BLCA progression by metabolism, the cell cycle and some carcinogenic pathways. A total of 249 hub genes were obtained from differentially expressed genes between ENO1-related ECs, and we used LASSO analysis to construct a novel signature that not only accurately predicted the prognosis of BLCA patients but also predicted the response to treatment for BLCA. Finally, we constructed a nomogram to better guide clinical application. In conclusion, through multi-omics analysis, we found that ENO1 was overexpressed in bladder cancer and associated with poor prognosis, CD8+ T-cell exhaustion and epithelial heterogeneity. Moreover, the prognosis and treatment of patients can be well predicted by constructing an epithelial-related prognostic signature.

Development of a Novel CD8+ T Cell-Associated Signature for Prognostic Assessment in Hepatocellular Carcinoma

OBJECTIVE

The aim of this study was to analyze the clinical significance and prognostic value of CD8+ T cell-related regulatory genes in hepatocellular carcinoma (HCC).

METHODS

This was a retrospective study. We combined TCGA-LIHC and single-cell RNA sequencing data for Lasso-Cox regression analysis to screen for CD8+ T cell-associated genes to construct a novel signature. The expression of the signature genes was detected at cellular and tissue levels using qRT-PCR, immunohistochemistry, and tissue microarrays. The CIBERSORT algorithm was then used to assess the immune microenvironmental differences between the different risk groups and a drug sensitivity analysis was performed to screen for potential HCC therapeutic agents.

RESULTS

An 8-gene CD8 + T cell-associated signature (FABP5, GZMH, ANXA2, KLRB1, CD7, IL7R, BATF, and RGS2) was constructed. Survival analysis showed that high-risk patients had a poorer prognosis in all cohorts. Tumor immune microenvironment analysis revealed 22 immune cell types that differed significantly between patients in different risk groups, with patients in the low-risk group having an immune system that was more active in terms of immune function. Patients in the high-risk group were more prone to immune escape and had a poorer response to immunotherapy, and AZD7762 was screened as the most sensitive drug in the high-risk group. Finally, preliminary experiments have shown that BATF has a promoting effect on the proliferation, migration and invasion of HuH-7 cells.

CONCLUSIONS

The CD8+ T-cell-associated signature is expected to be a tool for optimizing individual patient decision-making and monitoring protocols, and to provide new ideas for treatment and prognostic assessment of HCC.

The Metformin Immunoregulatory Actions in Tumor Suppression and Normal Tissues Protection

The immune system is the key player in a wide range of responses in normal tissues and tumors to anticancer therapy. Inflammatory and fibrotic responses in normal tissues are the main limitations of chemotherapy, radiotherapy, and also some newer anticancer drugs such as immune checkpoint inhibitors (ICIs). Immune system responses within solid tumors including anti-tumor and tumor-promoting responses can suppress or help tumor growth. Thus, modulation of immune cells and their secretions such as cytokines, growth factors and epigenetic modulators, pro-apoptosis molecules, and some other molecules can be suggested to alleviate side effects in normal tissues and drug-resistance mechanisms in the tumor. Metformin as an anti-diabetes drug has shown intriguing properties such as anti-inflammation, anti-fibrosis, and anticancer effects. Some investigations have uncovered that metformin can ameliorate radiation/chemotherapy toxicity in normal cells and tissues through the modulation of several targets in cells and tissues. These effects of metformin may ameliorate severe inflammatory responses and fibrosis after exposure to ionizing radiation or following treatment with highly toxic chemotherapy drugs. Metformin can suppress the activity of immunosuppressive cells in the tumor through the phosphorylation of AMP-activated protein kinase (AMPK). In addition, metformin may stimulate antigen presentation and maturation of anticancer immune cells, which lead to the induction of anticancer immunity in the tumor. This review aims to explain the detailed mechanisms of normal tissue sparing and tumor suppression during cancer therapy using adjuvant metformin with an emphasis on immune system responses.

Therapeutic significance of tumor microenvironment in cholangiocarcinoma: focus on tumor-infiltrating T lymphocytes

Cholangiocarcinoma (CCA) is a highly aggressive type of adenocarcinoma distinguished by its invasiveness. Depending on specific anatomical positioning within the biliary tree, CCA can be categorized into intrahepatic CCA (ICCA), perihilar CCA (pCCA) and distal CCA (dCCA). In recent years, there has been a significant increase in the global prevalence of CCA. Unfortunately, many CCA patients are diagnosed at an advanced stage, which makes surgical resection impossible. Although systemic chemotherapy is frequently used as the primary treatment for advanced or recurrent CCA, its effectiveness is relatively low. Therefore, immunotherapy has emerged as a promising avenue for advancing cancer treatment research. CCA exhibits a complex immune environment within the stromal tumor microenvironment (TME), comprising a multifaceted immune landscape and a tumor-reactive stroma. A deeper understanding of this complex TME is indispensable for identifying potential therapeutic targets. Thus, targeting tumor immune microenvironment holds promise as an effective therapeutic strategy.

Dissecting T-cell heterogeneity in esophageal squamous cell carcinoma reveals the potential role of LAIR2 in antitumor immunity

Esophageal squamous cell carcinoma (ESCC), one of the most commonly diagnosed and lethal malignant diseases, has a complex tumor ecosystem. An obvious requirement for T-cell-mediated tumor control is the infiltration of tumor-reactive T cells into the tumor. Here, we obtained detailed T-cell compositions in both ESCC tumors and matched peripheral blood mononuclear cells (PBMCs) at single-cell resolution. We demonstrated that T cells in tumors and PBMCs had different compositions and functional states. ESCC tumors were rich in Treg and exhausted T cells but poor in cytotoxic and naïve T cells compared with PBMCs. The exhausted T cells showed higher exhausted signature in tumors than in PBMCs, while the cytotoxic T cells exhibited higher cytotoxic signature in PBMCs than in tumors. Our data indicated an immunosuppressive status and a defect at the level of T-cell priming in the tumor microenvironment. Leukocyte-associated Ig-like receptor-2 (LAIR2), a soluble collagen receptor that prevents the binding of human leukocyte-associated Ig-like receptor-1 (LAIR1) to collagens, was predominantly expressed in proliferating CD8+ T and Treg cells in tumors but in cytotoxic cells in PBMCs. LAIR2 could inhibit tumor metastasis, invasion, and collagen deposition via suppressing transforming growth factor-β signaling. These findings revealed differential T-cell populations in tumors and PBMCs and provided convincing evidence that LAIR2 acted as a tumor suppressor.

Emerging Therapeutic Targets and Drug Resistance Mechanisms in Immunotherapy of Hematological Malignancies

CAR-T cell therapy has revolutionized the treatment of hematological malignancies with high remission rates in the case of ALL and NHL. This therapy has some limitations such as long manufacturing periods, persistent restricted cell sources and high costs. Moreover, combination regimens increase the risk of immune-related adverse events, so the identification new therapeutic targets is important to minimize the risk of toxicities and to guide more effective approaches. Cancer cells employ several mechanisms to evade immunosurveillance, which causes resistance to immunotherapy; therefore, a very important therapeutic approach is to focus on the development of rational combinations of targeted therapies with non-overlapping toxicities. Recent progress in the development of new inhibitory clusters of differentiation (CDs), signaling pathway molecules, checkpoint inhibitors, and immunosuppressive cell subsets and factors in the tumor microenvironment (TME) has significantly improved anticancer responses. Novel strategies regarding combination immunotherapies with CAR-T cells are the most promising approach to cure cancer.

Systemic immunological profile of children with B-cell acute lymphoblastic leukemia: performance of cell populations and soluble mediators as serum biomarkers

Background

Children with B-cell acute lymphoblastic leukemia (B-ALL) have an immune imbalance that is marked by remodeling of the hematopoietic compartment, with effects on peripheral blood (PB). Although the bone marrow (BM) is the main maintenance site of malignancy, the frequency with which immune cells and molecules can be monitored is limited, thus the identification of biomarkers in PB becomes an alternative for monitoring the evolution of the disease.

Methods

Here, we characterize the systemic immunological profile in children undergoing treatment for B-ALL, and evaluate the performance of cell populations, chemokines and cytokines as potential biomarkers during clinical follow-up. For this purpose, PB samples from 20 patients with B-ALL were collected on diagnosis (D0) and during induction therapy (days 8, 15 and 35). In addition, samples from 28 children were used as a control group (CG). The cellular profile (NK and NKT-cells, Treg, CD3+ T, CD4+ T and CD8+ T cells) and soluble immunological mediators (CXCL8, CCL2, CXCL9, CCL5, CXCL10, IL-6, TNF, IFN-γ, IL-17A, IL- 4, IL-10 and IL-2) were evaluated via flow cytometry immunophenotyping and cytometric bead array assay.

Results

On D0, B-ALL patients showed reduction in the frequency of cell populations, except for CD4+ T and CD8+ T cells, which together with CCL2, CXCL9, CXCL10, IL-6 and IL-10 were elevated in relation to the patients of the CG. On D8 and D15, the patients presented a transition in the immunological profile. While, on D35, they already presented an opposite profile to D0, with an increase in NKT, CD3+ T, CD4+ T and Treg cells, along with CCL5, and a decrease in the levels of CXCL9, CXCL10 and IL-10, thus demonstrating that B-ALL patients present a complex and dynamic immune network during induction therapy. Furthermore, we identified that many immunological mediators could be used to classify the therapeutic response based on currently used parameters.

Conclusion

Finally, it is noted that the systemic immunological profile after remission induction still differs significantly when compared to the GC and that multiple immunological mediators performed well as serum biomarkers.

Identification of signature of tumor-infiltrating CD8 T lymphocytes in prognosis and immunotherapy of colon cancer by machine learning

BACKGROUND

To explore the specific marker of CD8+ T cell subsets which are closely related to the prognosis and immunotherapy of patients with colon cancer.

METHODS

18 kinds of immune cell expression profile data sets were obtained from GEO database. Compared with other immune cell types, the specific markers of CD8 (+) T cells (TI-CD8) in colorectal cancer were screened. Regression analyses were used to further screen prognostic related genes and construct a prognostic evaluation model. The patients were stratified and analyzed according to the risk scores, KRAS mutation status, stage, lymphatic infiltration and other indicators. The landscape of infiltration level, mutation and copy number variation of immune subsets in high and low TI-CD8Sig score groups were compared and analyzed. The difference of drug response between high and low TI-CD8Sig score groups was analyzed. Differential expression of the model genes was verified by the HPA database.

RESULTS

Six prognostic-related CD8T cell-specific gene targets were further screened, and the prognostic evaluation model was constructed. The AUC value of the model is >0.75. FAT3 and UNC13C showed a high mutation state in the low-risk group, while USH2A, MUC5B et al. specifically showed a high mutation state in the high-risk group. Compared with the low-risk group, the high-risk group had lower effective rate of drug response. The expression of PD-1 gene was positively correlated with the level of TI-CD8Sig score.

CONCLUSION

The risk assessment model based on CD8T cell-specific marker genes can effectively predict the prognosis and the drug response of patients with CRC.

Expression of IDO1 in Tumor Microenvironment Significantly Predicts the Risk of Recurrence/Distant Metastasis for Patients With Esophageal Squamous Cell Carcinoma

In this study, we aimed to explore immune markers predicting locoregional recurrence/distant metastasis (R/M) for patients with esophageal squamous cell carcinoma (ESCC) post-surgical intervention by using a novel high-throughput spatial tool to quantify multiple immune proteins expressed in ESCC and lymphocytes in tumor microenvironment (TME-L). First, formalin-fixed paraffin-embedded tissues from surgical patients with ESCC (n = 94) were constructed on a microarray, which was then divided into discovery (n = 36) and validation cohorts (n = 58). Using a newly developed GeoMx digital spatial profiling tool, 31 immune proteins in paired ESCC and TME-L, morphologically segmented by PANCK and CD45, respectively, from the discovery cohort were quantified, releasing 2,232 variables. Next, the correlation matrix was analyzed using the Corrplot package in R Studio, resulting in 6 closely correlated clusters. The Least Absolute Shrinkage and Selection Operator regression scoring model predictive of R/M risk with superior specificity was successfully established based on the 3 following hierarchically clustered immune proteins: ARG1 in ESCC/PANCK+, STING, and IDO1 in TME-L/CD45+. Moreover, the expression of IDO1 in TME-L, rather than in ESCC, significantly predicted the R/M risk score with an area under curve of 0.9598. In addition, its correlation with R/M status was further validated by dual immunohistochemistry staining of IDO1 and CD45 in discovery and validation cohorts. Above all, our findings not only provide a more accurate scoring approach based on quantitative immune proteins for the prediction of R/M risk, but also propose that IDO1 in TME-L potentially plays a driving role in mediating R/M in ESCC.

Ginseng-derived nanoparticles reprogram macrophages to regulate arginase-1 release for ameliorating T cell exhaustion in tumor microenvironment

BACKGROUND

Lines of evidence indicated that, immune checkpoints (ICs) inhibitors enhanced T cell immune response to exert anti-tumor effects. However, T cell exhaustion has been so far a major obstacle to antitumor immunotherapy in colorectal cancer patients. Our previous studies showed that ginseng-derived nanoparticles (GDNPs) inhibited the growth of various tumors by reprograming tumor-associated macrophages (TAMs) and downregulated the ICs expression on T cells in tumor microenvironment (TME), but the underlying effector mechanisms remained unclear.

METHODS

The correlation between arginase-1 (ARG1) and T cells was computed based on the colorectal cancer patients in TCGA database. In vitro, we observed that GDNPs reprogrammed TAMs inhibited ARG1 release and ultimately ameliorated T cell exhaustion according to several techniques including WB, PCR, ELISA and flow cytometry. We also used an in vivo MC38 tumor-bearing model and administered GDNPs to assess their anti-tumor effects through multiple indices. The mechanism that GDNPs improved T cell exhaustion was further clarified using the bioinformatics tools and flow cytometry.

RESULTS

GDNPs reprogramed TAMs via reducing ARG1 production. Moreover, normalized arginine metabolism ameliorated T cell exhaustion through mTOR-T-bet axis, resulting in reduced ICs expression and enhanced CD8+ T cells expansion.

CONCLUSIONS

By regulating the mTOR-T-bet axis, GDNPs reprogramed macrophages to regulate ARG1 release, which further ameliorated T cell exhaustion in TME. These findings provided new insights into comprehending the mechanisms underlying the mitigation of T cell exhaustion, which may facilitate the development of innovative therapeutic strategies in the field of cancer treatment.

Immune-mediated cholangiopathies in children: the need to better understand the pathophysiology for finding the future possible treatment targets

Cholangiopathies are defined as focal or extensive damage of the bile ducts. According to the pathogenetic mechanism, it may be immune-mediated or due to genetic, infectious, toxic, vascular, and obstructive causes. Their chronic evolution is characterized by inflammation, obstruction of bile flow, cholangiocyte proliferation, and progression toward fibrosis and cirrhosis. Immune-mediated cholangiopathies comprise primary sclerosing cholangitis (PSC), autoimmune cholangitis and IgG4-associated cholangitis in adults and biliary atresia (BA), neonatal sclerosing cholangitis (NSC) in children. The main purpose of this narrative review was to highlight the similarities and differences among immune-mediated cholangiopathies, especially those frequent in children in which cholangiocyte senescence plays a key role (BA, NSC, and PSC). These three entities have many similarities in terms of clinical and histopathological manifestations, and the distinction between them can be hard to achieve. In BA, bile duct destruction occurs due to aggression of the biliary cells due to viral infections or toxins during the intrauterine period or immediately after birth. The consequence is the activation of the immune system leading to severe inflammation and fibrosis of the extrahepatic biliary tract, lumen stenosis, and impairment of the biliary flow. PSC is characterized by inflammation and fibrosis of intra- and extrahepatic bile ducts, leading to secondary biliary cirrhosis. It is a multifactorial disease that occurs because of genetic predisposition [human leukocyte antigen (HLA) and non-HLA haplotypes], autoimmunity (cellular immune response, autoantibodies, association with inflammatory bowel disease), environmental factors (infections or toxic bile), and host factors (intestinal microbiota). NSC seems to be a distinct subgroup of childhood PSC that appears due to the interaction between genetic predisposition (HLA B8 and DR3) and the disruption of the immune system, validated by elevated IgG levels or specific antibodies [antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA)]. Currently, the exact mechanism of immune cholangiopathy is not fully understood, and further data are required to identify individuals at high risk of developing these conditions. A better understanding of the immune mechanisms and pathophysiology of BA, NSC, and PSC will open new perspectives for future treatments and better methods of preventing severe evolution.

Diagnostic Value of Immunological Biomarkers in Children with Asthmatic Bronchitis and Asthma

Background and Objectives: This study aimed to investigate the diagnostic value of immunological biomarkers in children with asthmatic bronchitis and asthma and to develop a machine learning (ML) model for rapid differential diagnosis of these two diseases. Materials and Methods: Immunological biomarkers in peripheral blood were detected using flow cytometry and immunoturbidimetry. The importance of characteristic variables was ranked and screened using random forest and extra trees algorithms. Models were constructed and tested using the Scikit-learn ML library. K-fold cross-validation and Brier scores were used to evaluate and screen models. Results: Children with asthmatic bronchitis and asthma exhibit distinct degrees of immune dysregulation characterized by divergent patterns of humoral and cellular immune responses. CD8+ T cells and B cells were more dominant in differentiating the two diseases among many immunological biomarkers. Random forest showed a comprehensive high performance compared with other models in learning and training the dataset of immunological biomarkers. Conclusions: This study developed a prediction model for early differential diagnosis of asthmatic bronchitis and asthma using immunological biomarkers. Evaluation of the immune status of patients may provide additional clinical information for those children transforming from asthmatic bronchitis to asthma under recurrent attacks.

FGL1-LAG3 axis impairs IL-10-Producing regulatory T cells associated with Systemic lupus erythematosus disease activity

Background

Systemic Lupus Erythematosus (SLE) is a prototypic autoimmune disease, which is accompanied by liver damage. However, it remains unknown whether liver damage is associated with SLE progression.

Method

ology: HepG2 and L-02 cells were stimulated with cytokines, and FGL1 mRNA and protein expression levels were determined using Real-time PCR and ELISA, respectively. Regulatory T cells (Treg) isolated from healthy individuals as well as patients with SLE and SLE and liver damage (SLE-LD) were cultured with autologous effector CD4+T cells in the presence of a functional antibody or isotype control. The expression levels of LAG3, CD25, PD-1, CXCR5, ICOS and OX40 were evaluated by flow cytometry. FGL1, IL-10, IL-17a and IL-21 levels in serum or culture supernatants were quantified by ELISA.

Results

Patients with SLE-LD exhibits higher disease activity indices and anti-dsDNA antibody levels. Importantly, fibrinogen-like protein 1 (FGL1), a key factor released from the injured liver, is up-regulated in patients with SLE-LD and is associated with disease activity. FGL1 expression is induced by the inflammatory cytokine IL-6 signaling in hepatocytes. Higher expression of the FGL1 receptor lymphocyte activation gene 3 (LAG3) is detected in Treg cells from patients with SLE-LD. The FGL1-LAG3 signaling axis inhibits Treg cell proliferation and impairs the suppressive activity of Treg cells by limiting IL-10 secretion. Furthermore, FGL1-LAG3 signaling promotes the production of pathogenic IL-17a and IL-21 by CD4+T cells by reducing IL-10 level produced by Treg in patients with SLE.

Conclusions

The FGL1-LAG3 signal axis is a key mechanism that subverts the suppressive function of Treg cells. This may provide a new therapeutic target for SLE and SLE-induced liver damage.

Lower PTEN may be associated with CD8+ T cell exhaustion in diffuse large B-cell lymphoma

Initially discovered in chronic viral infection and then extended to tumor, 'T-cell exhaustion' is a broad term describing the response of T cells to chronic antigen stimulation. By definition, whether T-cell exhaustion occurs in diffuse large B-cell lymphoma (DLBCL) remains largely unknown because little has been described. Here, the immune-suppressing checkpoint molecules involved in T-cell exhaustion, including PD-1, PD-L1, TIM-3 and TIGIT, whose expression levels were analyzed in DLBCL, were retrieved from the GEPIA database. Compared with the normal control, CD8A, TNFA, IFNG and GZMA were markedly elevated in DLBCL, indicating that infiltrated CD8+ T cells predominate in DLBCL. Meanwhile, inhibitory immune checkpoints, such as PD-1, PD-L1, TIGIT and TIM-3 were drastically higher in DLBCL. PTEN, WNT2 and DKK3 expression were also appraised. It was revealed that PTEN was lower in DLBCL, without being statistically significant. In contrast with PTEN, DKK3 and WNT2 were shown to be pronouncedly higher in DLBCL relative to the normal control. Prognostically, only TIGIT was found to be associated with overall survival in DLBCL. Collectively, all the data we curetted from the GEPIA and TIMER 2.0 databases explicitly indicate that CD8+ T cell exhaustion took place, which may be linked with lower PTEN in DLBCL. To the best of our knowledge, this is the first bioinformatic report explicitly proposing that CD8+ T cell exhaustion occurs in DLBCL, which may be associated with lower PTEN.

Establishment and validation of an immune infiltration predictive model for ovarian cancer

BACKGROUND

The most prevalent mutation in ovarian cancer is the TP53 mutation, which impacts the development and prognosis of the disease. We looked at how the TP53 mutation associates the immunophenotype of ovarian cancer and the prognosis of the disease.

METHODS

We investigated the state of TP53 mutations and expression profiles in culturally diverse groups and datasets and developed an immune infiltration predictive model relying on immune-associated genes differently expressed between TP53 WT and TP53 MUT ovarian cancer cases. We aimed to construct an immune infiltration predictive model (IPM) to enhance the prognosis of ovarian cancer and investigate the impact of the IPM on the immunological microenvironment.

RESULTS

TP53 mutagenesis affected the expression of seventy-seven immune response-associated genes. An IPM was implemented and evaluated on ovarian cancer patients to distinguish individuals with low- and high-IPM subgroups of poor survival. For diagnostic and therapeutic use, a nomogram is thus created. According to pathway enrichment analysis, the pathways of the human immune response and immune function abnormalities were the most associated functions and pathways with the IPM genes. Furthermore, patients in the high-risk group showed low proportions of macrophages M1, activated NK cells, CD8+ T cells, and higher CTLA-4, PD-1, PD-L1, and TIM-3 than patients in the low-risk group.

CONCLUSIONS

The IPM model may identify high-risk patients and integrate other clinical parameters to predict their overall survival, suggesting it is a potential methodology for optimizing ovarian cancer prognosis.

High CD8+tumor-infiltrating lymphocytes indicate severe exhaustion and poor prognosis in angioimmunoblastic T-cell lymphoma

Background

Exhaustion of CD8+ tumor-infiltrating lymphocytes (TILs), characterized by the overexpression of immune checkpoints (IC), is a major impediment to anti-tumor immunity. However, the exhaustion status of CD8+TILs in angioimmunoblastic T cell lymphoma (AITL) remains unclear. Therefore, we aimed to elucidate the exhaustion status of CD8+TILs in AITL and its influence on prognosis.

Methods

The correlation between CD8+TILs and IC expression in AITL was analyzed using single-cell RNA sequencing (n = 2), flow cytometry (n = 20), and RNA sequencing (n = 20). Biological changes related to CD8+TILs exhaustion at different cytotoxic T lymphocyte (CTL) levels (mean expression levels of CD8A, CD8B, GZMA, GZMB, and PRF1) in AITL were evaluated using RNA sequencing (n = 20) and further validated using the GEO dataset (n = 51). The impact of CD8 protein expression and CTL levels on patient prognosis was analyzed using flow cytometry and RNA sequencing, respectively.

Results

Our findings demonstrated that the higher the infiltration of CD8+TILs, the higher was the proportion of exhausted CD8+TILs characterized by the overexpression of multiple IC. This was accompanied by extensive exhaustion-related biological changes, which suggested severe exhaustion in CD8+TILs and may be one of the main reasons for the poor prognosis of patients with high CD8+TILs and CTL.

Conclusion

Our study comprehensively reveals the exhaustion status of CD8+TILs and their potential negative impact on AITL prognosis, which facilitates further mechanistic studies and is valuable for guiding immunotherapy strategies.